Setting up your first freshwater tank
Everything for a healthy first freshwater aquarium: gear, setup order, cycling and adding fish.
A freshwater tank is the easiest way into the hobby, and a well-planned one stays healthy with little effort. The secret is setting it up in the right order and giving it time to cycle before fish go in.
What you’ll need
Filter
Seachem Tidal Power Filterhang-on-back, or a canister like the Sicce Mega Filtra
From $48.01
Choose size
a planted-tank substrate if you want live plants
From $15.83
Choose size
Step by step
- Pick the spot. Choose a level, sturdy surface away from direct sunlight and drafts, near an outlet. Plan for the full weight of water.
- Rinse and add substrate. Rinse gravel if the bag says to (many planted substrates should not be rinsed; check the label). Slope it slightly higher at the back.
- Add hardscape and plants. Place rock and wood first, then plants. Keep the front open for swimming room and easy cleaning.
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Fill with treated water. Tap water usually contains chlorine or chloramine, which harms fish and bacteria. Treat it with a water conditioner such as Seachem Prime, dosed per its label.
Seachem PrimeView product →
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Start the filter and heater. Let the heater reach your target temperature and confirm the filter flows steadily.
Sicce SCUBA Preset heaterView product →
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Cycle the tank. Add nitrifying bacteria and test ammonia and nitrite. Fish are ready to go in once both read zero. See Cycling a new tank.
Seachem StabilityView product →
- Add fish gradually. Start with a few hardy fish and add more over several weeks. Feed lightly; uneaten food becomes ammonia.
Weekly routine
- Change part of the water with conditioned tap water at a similar temperature.
- Rinse filter media in removed tank water, not tap water, so you keep the good bacteria.
- Test ammonia, nitrite and nitrate, especially in the first few months.
- Trim plants and wipe the glass. Small, regular care beats big clean-ups.
Choosing your first fish
Pick a few hardy species that suit your tank size and stay peaceful with each other. Check each fish’s adult size, temperature and water preferences before buying, and avoid mixing fin-nippers with long-finned fish. Add a small group first, wait, test, then add the next.
Common first-tank mistakes
- Skipping the cycle. “New tank syndrome” is ammonia building up before bacteria are established.
- Overfeeding. Feed small amounts that are eaten quickly.
- Cleaning everything at once. Replacing all the filter media and substrate at the same time removes the bacteria colony.
- Untreated top-off water. Treat any tap water you add.
Planning a planted tank? Seachem Flourite and CaribSea Eco-Complete are made for rooted plants, and the “How to use” notes on Flourish Excel list Seachem’s dosing.